MakerBot Upgrade. Source: Kaarsten/
MakerBot Upgrade. Source: Kaarsten/

Recently MakerBot released an upgrade to the MakerBot Replicator 2 extruder. This upgrade is designed to replace the plunger screw and make the extruder more effective.

A printed version of the upgrade has been available on Thingiverse for some time. However, we’re going to install the upgrade provided by MakerBot.

Print Your Own Extruder Upgrade

The Replicator 2 Extruder Upgrade, also known as the Spring-loaded Drive Block, is based on a design by whpthomas. This design is available on Thingiverse if you prefer to print the upgrade yourself. If you print the upgrade, you will have to purchase some hardware.  

Required Hardware

1 – Compression Spring (3/8” x 1-1/8” x 0.041”)

1 – Bearing (623Z – 3mm ID, 10mm OC, 4mm width)

2 – Counter Sunk Hex Head Screws (M3 x 10mm)

Installing the Extruder Upgrade

Please note: a video tutorial of installing the extruder upgrade is available below.

Tools required:

2 mm Hex Wrench

2.5 mm Hex Wrench

Extruder Upgrade Parts List:

Drive Block

Bearing Arm



Flathead Bolt


Shoulder Bolt

Steps to Install Your Extruder Upgrade:

Step 1. Unload any filament using the Unload script. From the menu select Utilities > Change Filament > Unload and follow the prompts on the screen.

Step 2. Unplug your MakerBot Replicator 2.

Step 3. Remove the plug from the top of the extruder motor.

Step 4. Use the 2.5 mm hex wrench to loosen the bolts on the front of the fan just enough to remove the motor.

Step 5.  Slide the motor out of the carriage.

Step 6. Remove the 2 bolts attached to the drive block with the 2 mm hex wrench.

Step 7. Bolt the new drive block base to the motor with the black flathead bolt. Ensure the other hole for the shoulder bolt lines up.

Step 8. Slip the bearing over the post of the bearing arm.

Step 9. Press the cover into place, over the bearing, so it fits snugly and is flush with the bearing arm.

Step 10. Place the spring over the peg on the drive block base.

Step 11. Line up the corresponding peg on the bearing arm so it fits over the other end of the spring.

Step 12. Squeeze the Drive Block and bearing arm so the shoulder bolt hole lines up.

Step 13. Insert the shoulder bolt and use the 2mm hex wrench to tighten the bolt.

Step 14. Slip the motor back into the carriage.

Step 15. Retighten the fan bolts.

Step 16. Reconnect the motor plug.

You’re now ready to load your favorite color of filament. You’ll load the filament just a little bit differently with the extruder upgrade in place. Run the load script, push the lever down, and push the filament in.